<?php
interface SQLComparisonOperators {
	// simple comparison operators
	const EQUALS = "=";
	const GREATER = ">";
	const LESSER = "<";
	const DIFFERS = "!=";
	const GREATER_EQUALS = ">=";
	const LESSER_EQUALS = "<=";
	const NULL_SAFE_EQUALS = "<=>";
	
	// pattern comparison operators
	const LIKE ="LIKE";
	const NOT_LIKE ="NOT LIKE";
	
	// in comparison
	const IN = "IN";
	const NOT_IN = "NOT IN";
	
	// range comparison operators
	const BETWEEN ="BETWEEN";
	const NOT_BETWEEN = "NOT BETWEEN";
	
	// null operators
	const IS_NULL = "IS NULL";
	const IS_NOT_NULL = "IS NOT NULL";
}